From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen

The use of seismic reflection data and seismic modelling of igneous intrusions has greatly improved the understanding of igneous intrusions in sedimentary basins. However, there are still uncertainties in the seismic images of such intrusions, because they can have a complex architecture and their i...

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Main Author: Hagevold, Sondre
Format: Master Thesis
Language:English
Published: The University of Bergen 2019
Subjects:
Online Access:https://hdl.handle.net/1956/20425
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spelling ftunivbergen:oai:bora.uib.no:1956/20425 2023-05-15T18:29:52+02:00 From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen Hagevold, Sondre 2019-06-25T22:00:13Z application/pdf https://hdl.handle.net/1956/20425 eng eng The University of Bergen https://hdl.handle.net/1956/20425 Copyright the Author. All rights reserved Intrusions 3D modelling Contact aureole Seismic modelling Botneheia Geological modelling 756199 Master thesis 2019 ftunivbergen 2023-03-14T17:40:10Z The use of seismic reflection data and seismic modelling of igneous intrusions has greatly improved the understanding of igneous intrusions in sedimentary basins. However, there are still uncertainties in the seismic images of such intrusions, because they can have a complex architecture and their imaging potential is dependent on several factors. For instance, igneous intrusions crystallise from magma, which introduce heat to the host rocks in which they enter, resulting in a zone of contact metamorphism. Therefore, the present study analyses the effect a contact metamorphic aureole has on the seismic expression of igneous intrusions, and how intrusion geometries are imaged in both 2D- and 3D-seismic data. Digital outcrop models from the locality of Botneheia, Svalbard, from both lidar-data and photogrammetry, are first used to generate realistic 2D- and 3D-geological models. A modelling workflow is then applied to efficiently turn outcrops of intruded rocks into synthetic seismic images, both in 2D and 3D, and to perform sensitivity analyses. The study highlights which impact a change in dominant frequency has on the detail-level for intrusions in seismic data, this without and with contact aureoles, two types of the latter being tested in the 2D cases. The contact aureoles lead to lowered reflection amplitudes and influence how the reflections of the intrusions are resolved, i.e. a strong combined reflection and/or individual ones, and thus add to the list of factors complicating the imaging of igneous intrusions. The obtained results demonstrate that the seismic expression of intrusions may vary from case to case, i.e. dependent on local factors, and that seismic modelling should aid interpretation of real seismic data. This study also opens the door for more comprehensive 3D modelling of igneous intrusions, especially by including detailed contact aureoles. Masteroppgave i geovitenskap GEOV399 MAMN-GEOV Master Thesis Svalbard Spitsbergen University of Bergen: Bergen Open Research Archive (BORA-UiB) Botneheia ENVELOPE(16.500,16.500,78.300,78.300) Svalbard
institution Open Polar
collection University of Bergen: Bergen Open Research Archive (BORA-UiB)
op_collection_id ftunivbergen
language English
topic Intrusions
3D modelling
Contact aureole
Seismic modelling
Botneheia
Geological modelling
756199
spellingShingle Intrusions
3D modelling
Contact aureole
Seismic modelling
Botneheia
Geological modelling
756199
Hagevold, Sondre
From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen
topic_facet Intrusions
3D modelling
Contact aureole
Seismic modelling
Botneheia
Geological modelling
756199
description The use of seismic reflection data and seismic modelling of igneous intrusions has greatly improved the understanding of igneous intrusions in sedimentary basins. However, there are still uncertainties in the seismic images of such intrusions, because they can have a complex architecture and their imaging potential is dependent on several factors. For instance, igneous intrusions crystallise from magma, which introduce heat to the host rocks in which they enter, resulting in a zone of contact metamorphism. Therefore, the present study analyses the effect a contact metamorphic aureole has on the seismic expression of igneous intrusions, and how intrusion geometries are imaged in both 2D- and 3D-seismic data. Digital outcrop models from the locality of Botneheia, Svalbard, from both lidar-data and photogrammetry, are first used to generate realistic 2D- and 3D-geological models. A modelling workflow is then applied to efficiently turn outcrops of intruded rocks into synthetic seismic images, both in 2D and 3D, and to perform sensitivity analyses. The study highlights which impact a change in dominant frequency has on the detail-level for intrusions in seismic data, this without and with contact aureoles, two types of the latter being tested in the 2D cases. The contact aureoles lead to lowered reflection amplitudes and influence how the reflections of the intrusions are resolved, i.e. a strong combined reflection and/or individual ones, and thus add to the list of factors complicating the imaging of igneous intrusions. The obtained results demonstrate that the seismic expression of intrusions may vary from case to case, i.e. dependent on local factors, and that seismic modelling should aid interpretation of real seismic data. This study also opens the door for more comprehensive 3D modelling of igneous intrusions, especially by including detailed contact aureoles. Masteroppgave i geovitenskap GEOV399 MAMN-GEOV
format Master Thesis
author Hagevold, Sondre
author_facet Hagevold, Sondre
author_sort Hagevold, Sondre
title From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen
title_short From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen
title_full From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen
title_fullStr From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen
title_full_unstemmed From outcrop to synthetic seismic: 2D and 3D modelling of igneous intrusions at Botneheia, central Spitsbergen
title_sort from outcrop to synthetic seismic: 2d and 3d modelling of igneous intrusions at botneheia, central spitsbergen
publisher The University of Bergen
publishDate 2019
url https://hdl.handle.net/1956/20425
long_lat ENVELOPE(16.500,16.500,78.300,78.300)
geographic Botneheia
Svalbard
geographic_facet Botneheia
Svalbard
genre Svalbard
Spitsbergen
genre_facet Svalbard
Spitsbergen
op_relation https://hdl.handle.net/1956/20425
op_rights Copyright the Author. All rights reserved
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